Welcome to BYC,
I have one that did the same thing, i used a water hose and hosed him down when he got that look in his eye, it took a couple days but he now understands that they are not food.
I make sure he goes with me all the time to feed the babies and today is the first day they were free ranging around the house, He did not bother any of them, didn't even give that look, you will learn the look and then letem have it with the hose, it's not mean, mine loves to swim but he hates the suprise water them chicks set off if he looks at them too hard.
I have found these pups grow fast so they really should be fed 3 times a day if you can swing it, that will help alot in controlling the urge to grab a running snack :
You know when i went to pick my pup a hen flew into the pen and them pups 8 pounced on her and she was gone, they were just hungry, i felt bad for the guy as he listed them ad livestock gaurdian dog, but i have delt with dogs/pups all my life and there is a difference between a savage attack and a newbee looking for a meal.
I am sure you got a great pup there just needs to learn that not everything is food when they get hungry.
Arn't they just the biggest puppies ya ever seen?